Re: Gpio reset handling

[Michal Simek <monstr-pSz03upnqPeHXe+LvDLADg@public.gmane.org>]

Grant Likely wrote:
> On Thu, Sep 17, 2009 at 12:46 AM, Michal Simek <monstr-pSz03upnqPeHXe+LvDLADg@public.gmane.org> wrote:
>> Grant Likely wrote:
>>> From what I've heard so far, I'd do it the same way but use something
>>> like "xlnx,microblaze-gpio-reset" for the compatible value.  As long
>>> as you document the binding and post it to the devicetree-discuss
>>> mailing list for review you should have no problem doing what you want
>>> to do.
>>>
>>> BTW, start with the "xlnx,microblaze-*" value for now.  A architecture
>>> neutral value can always be chosen at a later date if this proves to
>>> be useful.
>> Here I see some problems if we want to use one reset gpio pin with leds.
>> It not happen in these days but I expect to use it with heartbeat led.
>>
>> If I want to use new compatible node, I have to change BSP to support this
>> but I can through out this part of code very soon. And if I want to use
>> that node with leds then this is wrong.
> 
> I think you misunderstand me.  I'm saying create a new node which
> references a gpio from the gpio node.  So it would look something like
> this (adapting your original example):

> 
>                gpio_res: gpio@81400000 {
>                        compatible = "xlnx,xps-gpio-1.00.a";
>                        interrupt-parent = <&xps_intc_0>;
>                        interrupts = < 7 2 >;
>                        reg = < 0x81400000 0x10000 >;
> ...
>                        xlnx,gpio-width = <0x8>;
> ...
>                } ;
> 
> gpio-leds {
>        compatible = "gpio-leds";
>        heartbeat {
>                label = "Heartbeat";
>                gpios = <&gpio_res 4 1>;
>                linux,default-trigger = "heartbeat";
>        };
> 
>        green {
>                label = "Green";
>                gpios = <&gpio_res 5 1>;
>        };
> };
> 
> reset {
>        compatible = "xlnx,microblaze-reset";
>        soft-reset-gpio = <&gpio_res 1 1>;
>        phy-reset-gpio = <&gpio_res 2 1>;
> }

yep, this make sense to me too.

Thanks,
Michal







-- 
Michal Simek, Ing. (M.Eng)
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/
Microblaze U-BOOT custodian